The present invention relates to a toilet cover opening/closing device by which the toilet cover in the fully opened state is moved by a motor to a point in the closing direction and then rotates until it is in the fully closed state being initiated by the weight of the toilet cover itself.
The present invention relates to a toilet cover opening/closing device by which the toilet cover in the fully opened state is moved by a motor to a point in the closing direction and then rotates until it is in the fully closed state being initiated by the weight of the toilet cover itself.
When one visits a toilet and sees a toilet cover wide open, he or she will not be impressed with it and it is not sanitary either. Moreover, when a heater is built into the toilet seat, power consumption increases during the time the toilet cover is left open. To solve these problems, a variety of toilet cover opening/closing devices for automatically closing a wide-open toilet cover have been proposed.
Japanese Laid-open patent application No. H11-76103 is an example that discloses a toilet cover in which a motor moves a wide-open toilet cover to a point in the closing direction, and then, the toilet cover rotates (to a fully closed position) by its own weight. Here, gears mechanically connect all the components, motor through the rotary shaft of the toilet cover, and a torque limiter, provided in the middle of the force transmission path, turns on a motor until the toilet cover starts rotating under its weight and automatically turns off the motor as soon as the toilet cover reaches the point at which the self-weight initiated rotational motion begins. Nonetheless, the moment of the toilet cover is larger than the torque generated by the torque limiter, idling the torque limiter. Nothing prevents the toilet cover from making the self-weight initiated rotational motion in the closing direction. Further, to prevent sudden closure of the toilet cover, the rotary shaft of the toilet cover is always connected to a shock absorber through gears to respond to the shock absorber.
Japanese Laid-open patent application No. H11-76105 discloses another type in which a motor drives both a toilet cover and a shock absorber in an attempt to prevent a sudden closure of a toilet seat. As the toilet cover reaches the point where its self-weight initiates closing motion, the friction mechanism in the shock absorber breaks the rotational (closing) motion of the shock absorber itself to cause an idle spin until the timer stops the motor. In this mechanism, the toilet cover quietly closes due to the resistance from the shock absorber when the toilet cover makes the self-weight initiated rotary motion in the closing direction.
Nevertheless, in light of the above problems of conventional technologies: the former type assumes an idle spin of the torque limiter every time the toilet cover makes an opening or closing motion, requiring an expensive torque limiter with very high durability. Further, the point where the magnitude of torque of the torque limiter exceeds the moment of the toilet cover is a point where the toilet cover initiates its self-weight rotational (closing) motion: the declination starting point fluctuates due to inconsistency of torque that the torque limiter provides or (an additional variable such as) a (textile or knit) cover attached to the toilet cover, complicating the method of controlling the motor. Further, when a user manually opens the toilet cover connected to a motor, he must always apply a force that is larger than the torque generated by the torque limiter. This adversely affects handling ease of the toilet cover.
The former type assumes the shock absorber to rotatably support the toilet seat and toilet cover, as a result, the shock absorber is loaded with a large external force. To rotate the shock absorber itself, the joint between the guide portion in the rotation mechanism and the motor must be made very rigid. Moreover, a user manually opens the toilet cover initially taking advantage of the toilet cover""s moment, which is the initial main load, however, he must apply a force large enough to overcome the friction mechanism built into the motor to rotate the shock absorber itself later. In this method, the torque suddenly increases in the middle of the motion. This also adversely affects the handling ease of the toilet cover.
To overcome the above problems, it is desirable to provide an affordable toilet cover opening/closing device having a simple configuration with greatly improved handling ease thereof at the time of manual opening.
As a means to solve the above problems, the present invention provides a toilet cover opening/closing device that comprises: a rotary shaft for moving the toilet cover; and a driving means for rotating the rotary shaft to provide a rotational motion to the toilet cover from an inclined starting position where the toilet cover starts rotating in the closing direction by its own weight. The driving means further comprises: a motor that is rotatable both clockwise and counterclockwise; a driving member that is connected to the output shaft end of the motor; a slave member that is connected to the rotary shaft end; and a switching mechanism mechanically connecting or disconnecting the driving member with the slave member. When the motor rotates clockwise to lift the toilet cover from the fully opened position to the inclined starting position, the switching mechanism allows the slave member to move in response to the driving member. After the toilet cover reaches the inclined starting position, the mechanical linkage between the driving member and the slave member is released. As a result, the slave member moves in accordance with the self-weight initiated rotary motion of the toilet cover independent if the driving member and the driving member returns to its fully opened position in the toilet cover independent of the slave member taking advantage of the motor""s reversed spin.
Assume that one wants to rotate the toilet cover that is kept wide open as a result of the motor""s clockwise rotational motion in the closing direction. The driving member connected to the motor end and the rotary shaft end of the toilet cover are mechanically connected via a switching mechanism; the motor driving the rotational motion of the toilet cover in the closing direction. After the toilet cover reaches the point of self-weight initiated inclination, the switching mechanism mechanically disconnects the driving member and the slave member. In this configuration, the slave member being independent of the driving member can move in response to the self-weight initiated rotational motion of the toilet cover, and at the same time, the driving member being independent of the slave member returns to its original position, which is the fully opened position of the toilet cover. As a result, when a user manually opens the toilet cover, a responsive motion occurs at the slave member but not at the driving member connected to the output shaft end of the motor. The toilet cover can thus be closed with a minimum effort. In addition, the closure of the toilet cover can be minimal only by releasing the linkage between the driving member and the slave member. The method of controlling a motor can thus be made easy and the manufacturing of the mechanism can thus be cost effective.
In this invention, the switching mechanism has a structure, for example, in which the driving member pushes the slave member to move the toilet cover from the fully opened position to the inclined starting position, wherein the slave member and the driving member do not interfere with each other as long as the toilet cover""s self-weight initiates the motion of the slave member defined by the inclined starting position and the fully closed position.
In this invention, the switching mechanism has a structure in which a groove is provided on the driving member in such a manner that a part of the slave member makes a relative linear motion therein to move in response to the driving member when the toilet cover moves from the fully opened position to the inclined starting position. The shape and length of the groove from one edge to the other edge is set so as to cause: (1) the motor""s reversed spin providing the slave member with a rotational motion independent of the driving member after the toilet cover rotates from the fully opened position to an inclined starting position; and (2) the driving member is capable of returning to its original position independent of the slave member.
In this invention, it is preferable that the toilet cover further comprises a shock absorber for applying a resisting force to the self-weight initiated rotational motion exercised in the closing direction such that the speed of the self-weight initiated rotational motion that occurs between the inclined starting position and ends in the fully closed position is slowed down. In this configuration, a large noise does not occur at the time the toilet cover makes the self-weight initiated rotational motion in the closing direction. In this way, the toilet cover will not be damaged either.
For the motor of this invention, a stepping motor is preferable. This configuration causes the stepping motor to lose synchronism with the motion even though manual opening of the toilet cover interrupts the motor driven closing rotary motion. As a result, the user can open the toilet cover with little effort even though opening applies a force against the motor""s spinning direction.
In this invention, it is further preferable that the toilet cover further comprises a stopper that mechanically defines the original position and the end position of the driving member, which is in line with the rotational motion of the driving member that occurs between the fully opened position and the inclined starting position. In this configuration, when the motor driven closing motion of the toilet cover encounters an opening motion manually applied thereto resulting in displacement of the toilet cover from the target position that meets the duration of time the motor was on, the motor makes a reversed spin to initialize the position of the toilet cover utilizing the stopper. In this way, the next motion of the toilet cover can normally be driven. By controlling steps or a time, the toilet cover opening/closing device of the present invention thus accurately repeats the same motion all the time.